Descaling tool



O 1, 1967 J. F. NIEDZWIECKI DES CALING TOOL I INVENTOR. JOSEPH F N/EDZW/EGK/ Filed March 11, 1966 United States Patent 3,349,461 DESCALING TOOL Joseph F. Niedzwiecki, La Crosse, Wis., assignor t Ingersoll-Rand Company, New York, N.Y., a corporation of New Jersey Filed Mar. 11, 1966, Ser. No. 533,706 7 Claims. (Cl. 29-81) ABSTRACT OF THE DISCLOSURE A needle-type descaling tool which includes a fluid motor casing and a tubular sleeve removably attached to the casing. A needle holder is mounted in the forward end of the tubular sleeve. There is an axially reciprocal anvil having a cup-shaped end which is arranged so that it slides over one end of the needle holder. The bottom of the cup strikes the needles to deliver an impact.

This invention relates to a tool for delivering an axial impact to a workpiece such as metal or the like in order to remove an unwanted material or scale such as dirt, rust or slag on a weld seam. It is particularly well adapted to removing an unwanted scale from hard to reach places.

More particularly this invention relates to a needletype descaling tool. A descaling tool of this type employs a plurality of thin bits which are repetitively stuck by a reciprocating member, These bits are known in the art as needles.

In prior needle-type descaling tools, the needles are held in a thin holder which is fixed to an anvil. The holder is slidably mounted in a sleeve. When the anvil is struck by the hammer of a reciprocating piston, the holder as well as the anvil reciprocates. This results in a great deal of vibration and heating of the tool, especially when it is not in contact with the work, and the holder tends to come loose from the anvil, and the tool no longer functions properly. In prior descaling tools of this type where the holder is fixed to the anvil, when the needles need to be replaced, the anvil and needle holder must be removed from the tool and special equipment used to remove the holder from the anvil. This is a very difficult process when in the field since the proper equipment is not readily available.

It is therefore the principal object of this invention to provide a descaling tool which allows the needles to be changed without special equipment.

It is another object of this invention to provide a descaling tool which will operate for long periods of time.

It is a further object of this invention to provide a needle-type descaling tool in which vibration is reduced.

It is a still further object of this invention to provide a needle-type descaling tool which is cooler during operation.

In general, these and other objects are carried out by providing a needle-type descaling tool which has a body "with an impact motor which includes an axially reciprocating member or anvil having a generally cup-shaped end. A needle holder is fixed in the body and has a plurality of bores therethrough. The cup-shaped end of the reciprocating member slides over one end of the holder. A needle or bit slidably fits in each of the bores and extends out of the end of the body. As the member reciprocates, it strikes the needles which, in turn, will strike the surface of the workpiece.

These and other objects will become apparent from the following description and drawings in which:

FIG. 1 is a longitudinal section through a descaling tool of this invention; and

FIG. 2 is a cross section on the line 2-2 of FIG. 1.

Referring to the drawings, there is a body generally indicated at 30 which includes a casing 4 and a sleeve 5. Within the body there is an impact motor which includes a hammer 1' which is attached to a reciprocating piston 2. The piston reciprocates in a piston cylinder 3 mounted in 'a housing or casing 4. The piston may be reciprocatcd by any suitable power source. such as air under pressure.

Removably attached to the outside of the casing 4 is a hollow open-ended tubular sleeve 5 having a frustoconical shaped cap 6 at the forward end which provides a shoulder 29. The tubular sleeve 5 may be attached to the cylinder 3 by any suitable means such as threads or a coupling means such as that shown in U.S. Patent No. 3,150,888 issued to E. B. Parker.

Slidably mounted in the tubular sleeve 5 is an anvil or axially reciprocating member 7 having a shank 8 and a generally cup-shaped end 9. The casing 4 has a reduced diameter forward end 10 having an opening 11 A ball 12 is mounted within the opening 11. The shank 8 of the anvil has a cut-out portion 13. The ball is retained in the socket 11 by a sleeve, 15 which is secured to the housing by means of a snap ring 16. Two pair of O-rings 27 are interposed between the sleeve 15 and the housing 4 to act as shock absorbers. When the anvil 7 is struck by the hammer 1, it advances until the ball 12 meets the surface 14. A retainer such as this is described in greater detail in U.S. Patent No. 2,854,238 issued to E. D. Kennell.

An elongated holder 17 having a plurality of longitudinal bores 18 therethrough is mounted in the forward end of the tubular member 5. The forward end of the holder has an outwardly projecting flange 19 which rests on the shoulder 29 of cap 6.

The rearward end of the holder 17 loosely or slidably fits into the cup portion 9 of the anvil 7. Since the holder fits loose in the anvil, when the anvil reciprocates, the holder will remain fixed and not tend to reciprocate.

The spring 20 fits in the tubular member 5 between the flange 19 and the forward end of the cup-shaped portion 9 of the anvil, as clearly shown in FIG. 1, for biasing the anvil rearwardly when the piston 2 moves rearwardly. This spring also biases the holder against the shoulder 29 to keep it in place during operation of the tool.

A plurality of needles or bits 21 which may have a cutting edge at the forward end and has an enlarged opposite end 22 is slidably mounted in the bores 18 in the holder 17. Since the needle holder 17 is elongated, the needles tend to remain parallel. This promotes longer needle life and increased efliciency.

In operation, the cutting edges of the needle-type bits 21 is placed against the workpiece from which a scale is to be removed. This forces the enlarged end 22 of the bits against the bottom of the cup 9. Power is supplied to reciprocate the piston 2 and thus the hammer 1. The hammer strikes the shank 8 of the anvil, and the anvil 7 moves forward until the ball 12 meets the surface 14. The enlarged end 22 of the bits 21 are struck and the cutting edge of the bits strikes the workpiece. By using a plurality of bits which move relative to each other, scale may readily be removed from a workpiece of irregular shape or in an inaccessible location.

When the anvil moves forward, the spring 20 will be compressed and return the anvil 7. The piston and hammer are returned by the power source. If fluid is used as the power source, there may be a valve in the backhead of the tool which allows the fluid to reach the forward portion of the cylinder 3.

Because the holder 17 fits loosely in the cup-shaped portion 9 of the anvil, as the anvil moves forward, the holder will remain-stationary rather than be pushed and pulled as in prior designs. This means that there is less mass being reciprocated and, thus, less unnecessary vibration and generation of heat.

Additionally, by having the holder 17 fixed in the tubular member and loosely fit in the cup 9, should it be necessary to replace a needle, it can be done on the job without requiring unavailable equipment. In prior designs, the holder was generally elliptical in shape and was fixed in the cup-shaped poltion of the anvil. It was necessary to deform the cup member by using a vise, remove the holder from the cup member and then re move the needles.

By using the design of this invention, the tubular sleeve 5 is removed from the housing 4 and the holder remains in the sleeve while sliding free from the cup 9. Any broken needles can then be easily replaced, and the tool reassembled without equipment not usually available in the field. If it is desired to remove the holder, it may be pulled out of the sleeve 5.

Having fully described a preferred embodiment, it is intended that the scope of this invention be limited in no way except by the appended claims.

I claim:

1. A tool for delivering an axial impact to a workpiece comprising:

a body;

an impact motor mounted in said body having an axially reciprocating member;

a holder disposed in said body forward of said axially reciprocating member; and

a plurality of bits slidably mounted in said holder and extending out of said body and adapted to be struck by said member;

said reciprocating member having a cup-shaped end and being adapted to slide over one end of said holder, the bottom of said cup being adapted to strike said bits.

2. Apparatus according to claim 1 wherein said impact motor includes a fluid operated piston having a hammer attached thereto; said hammer adapted to strike said axially reciprocating member.

3. Apparatus according to claim 2 further including spring means mounted in said body for biasing said reciprocating member rearwardly.

4. Apparatus according to claim 3 wherein said holder is elongated and has a flange at the forward end thereof for engaging the inside of said body.

5. Apparatus according to claim 4 wherein said bits have enlarged heads at the end adapted to be struck by said member.

6. Apparatus according to claim 3 wherein said body includes a casing, a hollow sleeve, means for attaching said sleeve to said casing, means providing a shoulder within said sleeve, and said holder having a flange for engaging said shoulder.

7. The tool according to claim 1 including spring means mounted between said reciprocating member and said holder for biasing said reciprocating member rearwardly and said holder forwardly.

References Cited UNITED STATES PATENTS 1,911,813 5/1933 Decker 173-133 2,180,034 11/1939 Charles 173-133 X 2,226,559 12/1940 Groom 173l33 X 2,228,445 1/ 1941 DeVelbiss 299 X 2,356,314 8/1944 Gray et a1. 29--8l WALTER A. SCHEEL, Primary Examiner.

I. M. NEARY, Assistant Examiner. 

1. A TOOL FOR DELIVERING AN AXIAL IMPACT TO A WORKPIECE COMPRISING: A BODY; AN IMPACT MOTOR MOUNTED IN SAID BODY HAVING AN AXIALLY RECIPROCATING MEMBER; A HOLDER DISPOSED IN SAID BODY FORWARD OF SAID AXIALLY RECIPROCATING MEMBER; AND A PLURALITY OF BITS SLIDABLY MOUNTED IN SAID HOLDER AND EXTENDING OUT OF SAID BODY AND ADAPTED TO BE STRUCK BY SAID MEMBER; SAID RECIPROCATING MEMBER HAVING A CUP-SHAPED END AND BEING ADAPTED TO SLIDE OVER ONE END OF SAID HOLDER, THE BOTTOM OF SAID CUP BEING ADAPTED TO STRIKE SAID BITS. 